Induction-heater



0. A. COLBY.

INDUCTION HEATER.

APPLICATION FILED FEB. 25, I9I9.

Patented Dec. 27, 1921.

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ORA A. COLBY, IRWIN, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC 6c MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

' INDUCTION-HEATER.

Specification of Letters Patent. fPatellted D60. 27, 1921.

Application led February 25, 1919. Serial No. 279,157.

To'all whom t may concern.'

Be it known that I, ORA A. CoLBY,a citizen of the United States, and a resident of l Irwin, in the county of lVestmoreland and State of Pennsylvania, have invented a new and useful Improvement in Induction-Heaters, of which the following isa specification.

My invention relates to induction heaters and it has, for its primary object, the provision of a heater which may bey employed for heating liquids by employing a modified form of transformer which induces a heating-current of electricity in a suitable conduit, l

My invention provides a more compact structure than has been possible with devices known heretofore. For example, it may be employed in an oil-cracking still in which it has been customary to employ gas or similar fuels in supplying the neces- A sary heat. As such fuels necessitate employing relatively large stacks to carry away the gases formed by combustion, the structure for such work may `be considerably simplified by employing a heaterconstructed in accordance with my invention.

Another object of my invention is to provide a Iheater for liquids and the like in which the heat is generated in the liquidcarrying passage and, in which consequentl the efficiency of the device isM consideraby higher than with ordinary heaters lbecause of the heat saved by avoiding convection and other sources of loss.

A still further object of my invention is the provision of a heater in which the amount of heat transmitted may be automatically controlled.

With these and other objects in view, my invention will be more fully described, illustrated in the drawings, in the several views of which corresponding numerals indicate like parts, and then particularly pointed out in the claims.

In the drawings, Figure 1 is a side view .of

a vertical oil-cracking still, partly in elevation and partly in section, constructed in aca conduit possessing a relatively high resistance whichis contrary to the principle embodied in ordinary transformers in which the resist-ance of both the primary and secondary coils is usually reduced to a minimum. The secondary coil may be mounted about the laminated core between a plurality of primary coils which are, of course, insulated from each other and from the core. By supplying alternating currentto the pr'- mary coils, a current may be induced in the secondary coil or conduit which, by virtue of its high resistance, is heated, thereby imparting heat to a liquid passing therethrough.

F urthermoreif it isl found desirable, the heat, imparted to the liquid passing through the secondary coil, may be controlled by employing a thermostat to open or close the circuit of the primary coils, thereby controlling the heating current induced in the secondary coil.v y

In order to insure a clear understanding of my invention, Ihave shown, in Fig. l of the drawings, an oil-cracking still 1 comprising a suitable supporting-base-2 carrying' a heating-chamber 3. The heating-chamber 3 is preferably constructed so as to provide thermal insulation for a heating device contained therein. This may be accomplished in a vvariety of ways; for example, the heating-chamber 3 may comprise an interior lining 4 of metal, to insure sufficient rigidity of form, and this may be covered with a suitable'heat-insulating material 5.

.An outlet conduit 6, provided with thermal insulation 7, may be so mounted as to extend within the heating-chamber 3 and to the end of this may be attached an annular conduit 8 which is preferably of material possessing` relatively high electrical resistance. An inlet conduit 9 may be attached to the annular conduit 8 diametrically opposite-the conduit 6l and within the chamber 3 and may have, at its other end, a reservoir having a drain pipe 11 and an inlet pipe 12 in which may be inserted a valve 13.

' A core 14, preferably composed of superimposed laminations of steel, such as are employed in transformers, may be mounted so that one side thereof extends through the heating-chamber 3 and throughthe annular conduit 8. The portion of the core which passes through the heating-chamber and the conduit 8 may be covered with suitable insulating material, and primary coils 15 may be mounted thereon at opposite sides of the heating-chamber.

ln operating the device above described, oil is forced into the inlet pipe 12, preferably under suitable pressure, through the reservoir l0 into the conduit 9 and thence` Vinto the annular conduit 8.

rihe .annular conduit 8 serves as the secondary coil of the transformer and is heated by supplying electric current to the prima-ry coils 15 which induces a current in the secondary coil, in accordance with the Well known theory of transformers. A suitable current is thus supplied to heat the conduit 8, vthereby volatilizing and producing y`chem1cal reactions inthe oil which rises through the outlet conduit 6 and is conducted into Silitable vats.

The primary coils may be mounted at opposite sides of the heating-chamber and, being in close relation to the secondary coil, the reactance in the transformer core may be reduced. Furthermore, by so mounting to the top of the tank Where it may brancli into an outlet pipe 19 and an inlet p-ipe 20 to the tank. ln this instance, the liquidcarrying pipe is given a turn or two about the transformer core l@ upon which is also mounted a primary coil 21, both the primary coil and the secondary coil or pipe being insulated from the core, as indicated at 22.

The heat necessary for such service, in

most instances, is not excessive and the primary coil may be suiiciently insulated to protect it from anyheat generated in the closely related secondary coil. The close relation of the primary and secondary coils in this mdiied form insures very high ethciency, as the reactan'ce in the core is reduced 'to a minimum. Cold Water may be supplied to the inlet pipe 17 and led through the coil wound about the transformer core 18 Where it may be heated and conductedto the top of the tank 1d which' serves as a reservoir for' the heated Water when it is not being used as fast as it is heated.

In Fig.v 5 is shown, diagrammatically, a control system which may be employed in regulating the amount of heat generated in the device above described. A source of alternating current supplies current to the supply line 23, to one side of which is connected a contact-member V24 whichl is adapted to be connected to a contact-member .26 by a bridging-member of a relay 27. rl`he primary coil 28 of the transformer may be connected to the contact-member 26 and to the other side of the supply line 23. A. switch-actuating coil 29 is connected to the contact-member 24:` and to a contact-member 30 which is adapted to be connected to a contact-member 3l by the bridging-member of the relay 27. A switch-actuating coil 32 may be connected in series With the primary coil 28 and a thermostat 33 which is connected to the same side of the line as the freev end of the primary coil.

The action of the abovecontrol circuit is as follows: the bridging-member of the relay 27 connects the contact-members 24 and 26 in the heating position, thereby establishing'a circuit through the primary coil to the supply line 23.' The thermostat 33 may be adjusted to close the circuit which energizes the switch-actuating coil 32 when the heat reaches a predetermined value and, by so doing, the relay isoperated by the coil to dispose the bridging-member to close the circuit between contact-members 30 and 31, and, therefore, open the circuit of the primary coil 23. When the heat has been dissipated sufficiently, the thermostat 33 closes the circuit through the contacts 31 and 30 and switch-actuating coil 29 which, when energized, resets the bridging-member of the relay 27 across the contact-members 24- and"V 26, thus restablishing the circuit through the rimary coil to the transformer.

Although have described a plurality of structures in which a heating device ein bodying my invention may be employed and have set'forth, in detail, structural details of the heating device, it is obvious that minor changes may be made therein and many applications found therefor, and I de` sire that no limitations shall be imposed eX- cept such as are'indicated in the appended claims.

l claiml as my invention:

1. In an induction liquid heater, the combination with a metallic container for storing the liquid, of a laminated coreI a primary coil on said core, a metallic tube. wound around said core and forming a passage for the liquid to be heated and means for electrically connecting said tube to said container.

2. An induction liquid heater comprising core, a metallic huid-.carrying tube Wound around said core and adapted to form the around Ysaid core and means comprising a secondary coil, and means comprising a con- 10 metalliccontainer for storing the liquid and tainer for the liquid,y for completing the for completing the return electricalcircuit electrical circuit of said tube. of said tube. 1 i In testimony whereof, I have hereunto 3. An induction liquid heater comprising subscribed my name this 20th day of Feb.

ya laminated core, a primary coil on said 1919.

core, a metallic fluid-carrying tube Wound i ORA A. COLBY. 

